Removable insert for internal combustion chambers



1963 c. o. SPENCER ETAL 3,115,126

REMOVABLE INSERT FOR INTERNAL COMBUSTION CHAMBERS 4 Sheets-Sheet 1 Filed June 8, 1961 FIG.

V m 6 O 3 w 2 V 85 3 I I/ 4a 0 3 E I M m/W\O 2 2 5 m w u a w/ m N 9 mu! 3 u v u I l w 3 2 v A g BOYD L SPENCER I I (/4 v REMOVABLE INSERT FOR INTERNAL COMBUSTION CHAMBERS Filed June 8, 1961 Dec. 24, 1963 c. o. SPENCER ETAL 4 Sheets-Shqet 2 Isr1 SR u 0 Tm 5 E Q 2 WW I .5 W w. m B L mm o I MB 0 WE m S K Dec. 24, 1963 c. o. SPENCER ETAL 3,115,126

REMOVABLE INSERT FOR INTERNAL COMBUSTION CHAMBERS Filed June 8, 1961 4 Sheets-Sheet 3 FIG. ll

INVENTORS o. SPENCER SPENCER CHARLES BOYD L.

ATTORNEY Dec. 24, 1.963 c. o. SPENCER ETAL 3,115,126

REMOVABLE INSERT FOR INTERNAL COMBUSTION CHAMBERS 4 Sheets-Sheet 4 Filed June 8, 1961 P mm 2 M PC 6 FILM... V W. H n may 3 \\\\\\-y EL i @D United States Patent 3,115,126 REMOVABLE INSERT FOR INTERNz-tL CGMBUSTIUN CHAMBERS Charles 0. Spencer and Boyd lL. Spencer, both of 446) S. Tyler, Gladewater, Tex. Filed June 8, 1961, Ser. No. 115,764 Claims. {61. 123-4L77 'lhis invention relates to improvements in internal combustion engines and in particular relates to a removable insert utilized within the combustion chamber of an internal combustion engine expressly for the purpose of proving a durable combustion chamber containing the necessary openings such as valve seats, etc., which is particularly resistant to damage caused by thermal stresses.

In internal combustion engines in general, and especially in deisel engines Which normally use comprmsion ratios of to l and greater, damage within the combustion chamber, resulting from the thermal stresses encountered in service, are an ever present problem. This is particularly true with respect to the area Within the combustion chamber wherein the valve seats are provided. The valve seats must be of suflicient physical dimensions to withstand the mechanical stresses imposed upon them. Consequently, the combustion chamber, particularly in the valve seat area, is sufi'ioiently thick that heat transfer from the valve seat surface to the engine coolant is rather poor. This condition, coupled with the fact that the exhaust gases directly impinge against the exhaust valve seat surface and further in View of the fact that the valves themselves are cooled to a great degree by conduction to the valve seat, places a tremendous thermal stress upon the valve seats. Naturally, there are materials which can easily withstand such stresses. However, it is not feasible economically to construct an entire cylinder head of such materials. A good grade of gray cast iron or a cast nickel-iron alloy is most commonly used for the engine block and head material but such materials are not necessarily of such uniform quality as to stand up under prolonged service. In fact, it is accepted as inevitable that diesel cylinder heads in particular will eventually crack in service and require repair.

This problem has been an ever present one in the art and it is of primary concern in connection with this invention to provide a practical solution to the problem, which solution is economically feasible as well as structurally practicable.

More specifically, an object of this invention isto pro vide a combustion chamber insert particularly for internal combustion engines of elevated compression ratios, in which the insert is of high quality cast iron or alloy and is so constructed and related to the engine itself as to effect a rapid and efiicient heat transfer from the valve seat area to the engine coolant, thus reducing the thermal stress on the insert and also maintaining the valve heads at a lower temperature, increasing their service life expectancy.

Still more specifically, an object of this invention resides in the provision of a combustion chamber insert for internal combustion engines in which the insert encompasses the valve seat area and other openings so that the valve or valves seat directly thereupon and wherein engine coolant passages are formed in the insert, having connections with the engine coolant system, so that the insert is characterized by a maximum of heat transfer particularly from the valve seat area.

A further object of this invention is to provide a combustion chamber insert having preformed passages therein connected to the coolant system of the associated internal combustion engine in which the passages are so formed as to cause a uniform and efiicient flow around that area 3,ll5,l2h Patented Dec. 24, 1963 "ice or areas of the insert in which the valve seat surface and necessary openings are formed.

A further object of this invention is to provide an insert of the character exemplified in the preceding paragraph in which the means for holding the insert in place constitutes in part or in whole the means by which the passages of the insert are communicated with the entire coolant system.

The novel features that are considered characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, wherein like reference characters indicate like parts throughout the several figures, and in which:

FIGURE 1 is a sectional view taken through a portion of an internal combustion engine showing an insert constructed in accordance with the invention incorporated therein;

FIGURE 2 is a plan view of a portion of a cylinder head having an insert therein;

FIGURE 3 is a horizontal section taken on section line 3-3 in FIGURE 1, showing the coolant passage system embodied in the insert;

FIGURE 4 is a vertical section taken on section line 4-4 in FIGURE 2, showing further details of the insert and its manner of securement as well as the means by which the passage system is connected to the engine coolant system;

FIGURE 5 is a perspective view of a portion of an internal combustion engine showing diagrammatically the coolant system connection for an insert passage system;

FIGURE 6 is a view similar to FIGURE 1, but showing a modified form of insert;

FIGURE 7 is a view similar to FIGURE 2, showing the modified insert of FIGURE 6;

FIGURE 8 is a horizontal section taken on section line 88 of FIGURE 6 illustrating the coolant passage system of the modified insert;

FIGURE 9 is a vertical section taken on section line 9-9 of FIGURE 7, showing further details of the modified insert and its manner of connection to the engine coolant system;

FIGURE 10 is a View similar to FIGURE 5, showing the fully external connection system for the passage sysstem of the modified insert;

FIGURE 11 is a sectional view similar to FIGURE 1, but showing a modified form of assembly;

FIGURE 12 is a bottom plan view of the insert constructed in accordance with FIGURE 11 and illustrating the disposition of the water inlet bolt relative to the insert;

FIGURE 13 is a horizontal sectional view through the insert shown in FIGURE 11 and taken on line 13--13 thereof;

FIGURE 14 is a perspective view of a further modified form of insert of sectional form for permitting of cleaning the same;

FIGURE 15 is a horizontal cross-sectional view taken through a portion of the assembly shown in FIGURE 14 and showing the manner of connecting the sections;

FIGURE 16 is a fragmentary cross-sectional view taken on line 16-416 of FIGURE 15;

FIGURE 17 is a vertical cross-sectional view taken through a still further modified form of the invention;

FIGURE 18 is a fragmentary cross-sectional view of a modified form of insert of the type shown in FIGURE 17, and

FIGURE 19 is a fragmentary cross-sectional view of another modified form of insert.

In the form of the invention shown in FIGURE 1, a cylinder head is shown in association with an engine block 11, the latter having one or more cylinders 12 therein surrounded by a water jacket 21. The head has an upper wall 13 and a lower wall 14 defining a water jacket 16, with a boss portion 15 projecting from the cylinder bore 12. The head is secured to the block by any conventional arrangement, not shown, and a conventional cylinder head gasket 17 may be interposed between the head and block. The head water jacket 16 may be of conventional character and in communication with the jacket 21 of the block 1 1 in the usual manner.

The boss portion 15 of the head is provided with a recess 18 opening through the lower wall 14 into the cylinder bore 12. An insert 19 is fitted in the recess 18, and it will be noted that the insert is slightly smaller diametrically than the recess to provide clearance space 20 therearound. The insert itself is so formed as to have an upper wall 21, a lower wall 22 vertically spaced from the upper wall 21 and a side wall 23 interconnecting the upper and lower walls peripherally of the insert. The spaced upper and lower walls 21 and 22 provide for an internal passage system more fully described hereinafter.

The insert 19 is held in place in the cylinder head recess 18 by means of a plurality of threaded bolt members 24, 25 and 26, and preferably these bolts are tubular and also provide means by which the internal passage system of the insert is connected to the coolant system of the engine so as to assure a constant flow of coolant therethrough. 'In the form shown, the insert has through openings 29 and 3a surrounded by countersunk portions 27 and 28, respectively, in the lower wall 22, and corresponding through openings 31 and 32 in the upper wall 21, and the boss 15 has registering internally threaded openings 33 and 34. Two of the fasteners, 24 and 26, have their enlarged heads nested in the countersunk portions 27 and 28, extend throughthe aligned openings 29, 31 and 39, 32, and are threaded in the openings 33 and 34, respectively.

conventionally, the fasteners 24 and 26 may be of the polygonally recessed head type, as shown in FIGURE 2, so that they may be removed and replaced with an Allen wrench type of tool and they are effective to hold the insert in place by the head. Obviously, other standard forms of fastener heads may be used. The fastener 25 is inserted from outside the engine, and passes through the upper Wall 13 of the cylinder head, the recessed wall of the boss 15 in the lower Wall 14 of the cylinder head, the upper wall 21 of the insert, and is threaded into an internally threaded hole in the lower wall 22 of the insert.

For ease of production both of the insert and the cylinder head, the insert is preferably of circular form with the fasteners 24 and 26 lying on a common diameter thereof and with valve port openings 35 and 36, FIG- URE 3, formed on a further common diameter oriented at 90 degrees to the diameter containing the fasteners 24 and 26. This arrangement need not, however, be strictly adhered to, the principle of operation being unaltered by other and different orientations and arrangements.

The valve ports 35 and 36, as best shown in FIGURES 3 and 4, are formed by annular wall portions 4%) and 41 connecting the upper and lower insert walls 21 and 22 and at once form these parts and operate, in part, to form the passage system hereinafter described. Reinforcing ribs 46 and 47 interconnect the upper and lower walls 21 and 22 of the insert and complete the passage system thereof. To this end, each rib is provided with a pair of roughly triangular wings 48 and 49, separated as shown, and interconnected by an arcuate bridge portion 50. The ribs 46 and 47 are symmetrically arranged with respect to the valve port walls 4%) and 41 and coopcrate therewith and also with the insert side wall 23 to form the passage system.

The passage system includes a blind inlet 55 formed between each pair of Wings 48 and 4-9 of each rib 46, 47 with each inlet being blocked at its inner end by a corresponding bridge portion 50. The outer ends 56 and 57 of each pair of wings are convex to provide canals 58 and 59, between the wings and the side wall 23, leading to the respective inlets 55. The inner sides 60 and 61 of each pair of wings 48 and 49 are concave to provide fairly uniform branches 62 and 63 leading from the area of fastener 25 to the canals 58 and 59 respectively. It will be noted that the points 70 and 71 of wings 48 and 49 are so located as to connect branches 62 and 63 at acute angles with canals 58 and 59 so that, as hereinafter described, the coolant flow within the passage system will be assured in the regions 72 and 73 between the outer sides of the port walls 40 and 41 and the side wall 23 of the insert.

The idea is, of course, Ito achieve as uniform coolant flow around the port walls 49 and 41 as is possible to effect an even cooling of the valve seat area.

The coolant is introduced into the passage system through the fastener 25 and flows therefrom through fasteners 24 and 26 into water jacket 16. To this end, it will be noted from FIGURES =1 and 4 that fastener 25 has a blind bore therein, being blind at the threaded end of the fastener and is provided adjacent its threaded end with lateral openings 81 and 82 located as shown and preferably directly towards the respective valve port walls 40 and 41. Also, fastener 25 is provided with an external extension 85, FIGURE 1, beyond the hexagonal portion 86 thereof which provides a nipple to receive a flexible line 87 leading to a point of more pressure in the coolant system than the internal jacketing of the engine is subjected to, thereby insuring coolant at areas which, with conventional water systems, are in some cases commonly known as steam pockets and create great stresses. Fasteners 24 and 26, on the other hand, have blind bores 94) and 91 the-rein which are blind at the head end of the fasteners and thus communicate directly with the water jacket of the head. Each fastener 24 and 26 has a lateral opening, shown at 92 and 93 respectively, leading into the inlets 55. Thus, the coolant flow may be pressured or sprayed through openings 81 and 82, into the canals 62 and 63 and then into the branches 58 and 59 to the openings 92 and 93 of the fasteners'24 and 26.

Thus it will be seen that the coolant passage system within the insert is specifically adapted to assure a controlled positive and substantially uniform coolant flow around the walls 40 and 41. As shown more clearly in FIGURE 4, these walls 40 and 41 effect continuations of the manifold ports 94 and 95 respectively which are formed integrally in the cylinder head and have the conventional valve guides 96 and 97 associated therewith to guide the stems of valves 98 and 99, the heads of these valves being seated upon the valve seat surfaces formed directly in the insert. The valve porting in the head and the valve assemblies are entirely conventional and form no part of this invention. However, FIGURE 4 serves to show how the proper coolant flow around the walls 40 and 41 will assure excellent cooling of the valve seat areas and consequently permit the valve heads to operate at a lower temperature. t The insert is preferably countersunk in the regions of the fasteners 24, 25 and 26 on the upper surface of the insert and indicated by reference characters 100, 101 and 102, which may receive gaskets as shown or O-rings or similar sealing means to prevent leakage at these points. Likewise, gaskets, as shown, may be used under the heads of fasteners 24 and 26 to prevent leakage. Of course, a full gasket may be interposed between the upper surface of the insert 19 and recess 18, with holes in the gasket to accommodate the valve and bolts. Counterborcs 100,

101, 102 would not be necessary when a full gasket is used.

A spark plug or injector nozzle assembly, such as the case may be, projects through a suitable opening 103 in the insert, which opening is threaded to receive such device. In FIGURE 2, an injector 104 is shown. The spark plug or fuel injector is otherwise mounted and related to the cylinder head in the usual manner.

FIGURE illustrates the external connection for the insert coolant passage system, it being understood that there will be similar connections for each insert of each cylinder when there are a plurality of cylinders. The cylinder head is provided externally with the usual gooseneck 105 having a return hose connection 1116 to the radiator, not shown. The front of the block mounts a conventional water pump 107 having the usual pulley driven shaft also mounting the fan 108 so that the coolant is drawn through the inlet hose connection 169 which extends from the radiator to the inlet branch 110 of the pump. The pump v11W may be connected to the engine block in the usual manner but in lieu or in addition, it is also connected to the external line 87 so that the lower temperature coolant is supplied at higher pressure through the fastener 25 while the bores 91) and 9 1 of fasteners 24 and 26 are subjected to the lower coolant pressure present internally of the block.

Referring now more particularly to FIGURE 6, wherein a modified form of insert is shown, it will be seen that the coolant system is entirely external. For this purpose, inlet and outlet fasteners .120 and 121 respectively are utilized. The insert 122 is fitted within recess 123 in the cylinder head 124, the dimensions of which are larger than the cylinder bore 125, in the cylinder block 126 so that the marginal edge of the insert overlaps the upper block face so that usual bolts which secure the cylinder head to the block also serve to maintain the insert within the head. To this end, the lower face of the insert is flush with the block-face of the cylinder head.

The insert itself includes the upper wall 127, the lower wall 128 and the side wall 129. Openings 130 and 131 in the upper wall pass the fasteners 121 and 120 respectively and aligned threaded bores in the lower wall threadedly receive the lower extremities of these fasteners. Both fasteners are similarly formed and have blind bores 139 therein, blind at the threaded ends of the fasteners, and shank portions 133 and 134 above the hexagonal shoulders 135 and 136 so that the hoses 137 and 138 may be connected thereto. Each fastener has a pair of lateral openings 139 and 140 shown in FIGURE 9 communicating with the interior coolant passage system of the insert.

As shown in FIGURE 8, the upper and lower walls of the insert are interconnected by the circular valve port walls 141 and 142 and by the serpentine ribs 143 and 144.

The rib 143 has an arcuate bridge portion 150 while the corresponding portion of the rib 144 has a gap 151, such bridge 151i and gap 151 being disposed in spaced relation at about the center of the insert on either side of fastener 120. The two limbs 152 and 153 of rib 143 are arcuate and are closely spaced to opposed portions of walls 141 and 142 to form restricted branches 154 and 155. The limbs 156 and 157 of rib 144, on the other hand, are also arcuate but are spaced further from the walls 141 and 152 and diverge therefrom to provide relatively unrestricted branches 160 and 161. Thus, as can be seen in FIGURE 8, a greater volume of coolant will flow through branches 161 and 161 as compared with branches 154 and 155 since a greater circumferential area of walls 141 and 142 must be cooled by the coolant thus flowing. The directional arrows in FIGURE 8 adequately illustrate the coolant flow from the fastener 12%, completely around the walls 141 and 142, to the outlet fastener 121, and also through the gap 151 to the outer wall of the insert. Ribs 143 and 144 act as reinforcement to combustion pressure.

FIGURE 6 also illustrates the solid portion connecting the upper and lower walls of the insert which is counterbored as at 171 and threaded as at 172' to receive the tip end of injector nozzle 172. In this respect, the insert 122 is identical with the insert of FIGURE 1. The gasket seals for insert 122 are also similar to insert 19,- as is the valve system, see particularly FIGURE 9, or a full gasket may be used. The nozzle seat 170 is cooled by coolant passing through the gap 151.

FIGURE 10 shows the external coolant system, the hose 137 being connected to the pressure side of water pump 181i and the hose 138 being connected to gooseneck 181 so that positive flow through the insert will be achieved.

Referring now more particularly to FIGURES 11-13, inclusive, the modified form of construction therein incorporates an insert indicated generally by the reference character 2% which is constructed generally along the principles of the insert described in conjunction with FIGURE 1. However, there are certain differences appertaining thereto and more specifically relating to the means for inducting and educting water into the insert assemblage.

In FIGURE 11, the cylinder head of the associated internal combustion engine is indicated generally by the reference character 2131 and the cylinder block thereof by the reference character 292. The. cylinder block includes the bore 2113 with which the insert 200' is associated. The head 2111 is recessed, as at 204, to receive the insert 2%, with the bottom surface 205' of the insert substantially flush with the bottom surface 206 of the head 201. As before, a conventional cylinder head gasket 2i)7 is employed between the cylinder head 201 and the block assembly 2112.

The insert 2% itself is of a dimension so as to provide a slight clearance 21% circumferentially therearound so that expansion and contraction of the cylinder head 2111 and of the insert Ziliiwill not cause interference between these two members and consequent undue stress concentrations upon the insert or the head such as the case may be.

As is shown most clearly in FIGURE 13, the upper wall 212 of the insert 2% is provided, on its inner surface, with the water deflecting means indicated generally by reference characters 213 and 214, and is provided with an opening 215 for educting water from within the hollow space within the insert and is provided with a further opening through which the hollow bolt 216 passes for inducting Water into the hollow space within the insert. As is shown in FIGURE 11, the two deflecting means 213 and 214 extend between the upper and lower walls 212 and 220 of the insert, these Walls being further joined by the circumferentially extending wall 221 substantially as is shown. The two walls 212 and 220 are further provided with aligned openings for receiving the injector assembly 221', such openings being provided through a boss 222 extending between the. upper and lower walls 212 and 220 and which boss isolates the'injector 221 from the interior of'the insert.

Valve passage forming members 223 and 224 also may be provided when necessary, extending between the upper and lower Walls 212 and 221 of the insert assemblage, substantially as is shown in FIGURE 13, and providing the valve openings 225 and 226 as is illustrated in FIGURE 12.

It will be seen that the boss 204 of the cylinder head 'assembly'2tl1' is provided with an aperture 227 which is aligned with the aperture 215 in the insert so as to permit the passage of water from the hollow space of the insert into the water jacketing 228 of the cylinder head. The rib or deflecting means 213 is interposed between the hollow bolts 216 and the outlet passage 215 in the insert, see particularly FIGURE 13, and the deflector means or rib'214is so arranged relative to the valve passage means 223 and 224 and to the circumferentially extending wall portion 221 of the insert so as to direct the water emanating from the hollow bolt 216 most advantageously for uniform cooling of the insert particularly in the critical areas thereof as the same passes from the hollow bolt 216 eventually to pass outwardly from the insert through the discharge passage or opening 215 and into the water jacketing 228 of the cylinder head 201. It will be noticed that the hollow bolt 216 is somewhat offset radially from the center of the insert 200, see particularly FIGURES 12 and 13. The reason for this is to absolutely ensure proper initial positioning of the insert 200 and to prevent accidental rotation thereof during usage. This sort of arrangement is desirable particularly in view of the fact that the outlet passages 215 and 227 must of necessity be fairly accurately aligned in order to establish the proper water flow through the insert assemblage. The hollow bolt 216 itself is similar in construction, arrangement and purpose as the hollow bolts previously described in conjunction with this invention.

As a further modification, allowing the insert to be cleaned periodically so as to remove rust, scale or the like which might impair its cooling properties, particularly in the region of the valve seats, a sectionalized insert such as is shown in FIGURES 1416 may be used. This insert is indicated generally at 300, and comprises a main body 301 including a front or firing face wall 302 and a spaced rear wall 303 rigidly connected by valve port passages 304 and 306 and which has a pair of removable segmental side wall sections 308 and 310.

The side walls are clamped on the body 301 by a pair of diametrically opposed fasteners 314. The edges of the end Walls 302, 303 are rabbeted at 302 and 303' to nest the edges of the side wall sections 308, 310. The abutting ends of the side wall sections 308, 310 are provided with gaskets such as the gaskets 320 shown in FIGURE 15, and -ring type seals or gaskets 324 and 326, FIGURE 16, such as split copper O-rings to enable spreading for fitting over the edges of the end walls, may be seated in the rabbets 302', 303 in any convenient manner to seal between the insert body 301 and the upper and lower edges, respectively, of the side walls 308 and 310.

l The fasteners 314 are so mounted as to be either flush or recessed so as not to protrude from the body of the insert. The insert shown in FIGURES 1416, like the modification shown in FIGURE 17 and hereinafter described, may be mounted and connected to the coolant system in any desired manner as previously described.

Referring to FIGURE 17, the further modification shown therein incorporates a body portion 318 provided with ports 328 and 330, and having a coolant chamber system such as the chambers 332 opening into the underside thereof. The chamber system may incorporate the principles as above described. The removable inspection and cleaning plate in this case comprises a bottom wall 312 secured by fasteners 334 having their heads recessed within the bottom wall as shown. A suitable gasket 322 is interposed between the body 318 and bottom wall 312, and both the gasket and bottom wall are provided with openings registering with ports 328 and 330.

As the major wear and/or cracking in engine heads is immediately around the valve seats, valve seat elements may be removably mounted in the inserts themselves. Any suitable arrangement may be employed in any of the aforementioned inserts, but the separable insert structure shown in FIGURE 17 is particularly suitable. As shown in FIGURE 18, the main body portion 318' may be provided with removable valve seat and passage portions 328 positioned from the rear of the body portion and retained by the bottom wall 312 and fasteners 334. The front wall of the body portion 318 may have openings 336 defined by flanged or stepped edges for receiving stepped flanges 338, as shown, and a gasket 340 may be interposed therebetween. Obviously, the

edges of the openings 336 and the flanges 338 may be tapered or of any other configuration that will serve to retain the valve seat portions 328' in position. By this arrangement, the valve seat portions 328 may be formed of tougher or otherwise more suitable metal than the body portions and may be readily replaced when the seats become worn or deformed.

In the systems according to FIGURES 14-18, periodic inspection and cleaning of the inserts are made possible, to the end of maintaining good heat transfer characteristics through the walls of the inserts.

Another form of removable valve seat element that is suitable for integral as well as separable inserts is shown in FIG. 19. For convenience of illustration, this valve seat element 32812 is shown in association with a separable insert of the type shown in FIG. 17 and having a body portion 318a with valve sleeve portions 328a for receiving the element 328b with a snug driving fit.

The sleeve portions 328a and element 328!) have interengaging shoulders 2342 for accurately locating the element which extends the full height of the insert including the body portion 313a, gasket 322' and bottom wall 312', the latter two having enlarged holes for receiving the enlarged end of the element 32%. In assembling this structure, the wall 312' is bolted to the body portion 318a and the gasket 322 is squeezed so that it functions as an O-ring when the element 328i; is driven in. As the element 323!) extends the full height of the insert, obviously it is adaptable for integral inserts such as shown in FIGS. 1l3.

Although certain specific embodiments of the invention have been shown and described, it is obvious that many modifications thereof are possible. The invention, therefore, is not to be restricted except insofar as is necessitated by the prior art and by the spirit of the appended claims.

What is claimed is:

1. In an internal combustion engine and including a cylinder block having a combustion chamber and a cylinder head removably attached to the block and closing said chamber, said head being hollow in the region above said chamber, an insert received in said cylinder head and forming at least a portion of the combustion chamber thereof, said insert being hollow, and means removably attaching said insert to the cylinder head including means by which the interior of the insert is connected to the interior of said head.

2. In an internal combustion engine having a cylinder block and a cylinder head removably attached thereto, an insert fixed .to said head to form at least a portion of the combustion chamber surface for the engine, said insert having an upper wall and a lower wall spaced from the upper wall, and a side wall joining the upper and lower walls marginally thereof to provide a hollow interior for the insert, a pair of coolant conduit means providing spaced inlet and outlet openings communicating with the interior of said insert and including a hollow bolt passing through the insert and having a lateral opening therein, said insert also including cylindrical valve port walls extending between the upper and lower walls thereof, and first and second reinforcing rib means extendingbetween the upper and lower walls thereof, said first and second reinforcing rib means being disposed in partially embracing relation to said valve port walls, one of said coolant conduit means communicating with the interior of said insert between said first and second reinforcing rib means and the other coolant conduit means being spaced therefrom beyond one of said reinforcing rib means.

3. In an internal combustion engine having a cylinder block and cylinder head removably attached thereto, an insert fixed to said head to form at least a portion of the combustion chamber surface for the engine, said insert having an upper wall and a lower wall spaced from the upper wall, and a side wall joining the upper and lower walls marginally thereof to provide a hollow interior for the insert, means for attaching the insert to the cylinder head including a hollow bolt passing through the insert and having a lateral opening therein communicating with the interior of the insert, said insert also including cylindrical valve port walls extending between the upper and lower walls thereof and reinforcing ribs extending between the upper and lower walls thereof, said reinforcing ribs being positioned with respect to said valve port walls so as to provide coolant directing passages extending completely thereatround each of said reinforcing ribs including a pair of wings of generally triangular form interconnected by arcuate bridge portions, opposed sides of said wings forming an inlet therebetween extending from said bridge portion and having other sides of generally concave configuration spaced from portions of said cylinrical walls to form narrow passages therewith, said means for attaching the insert to the cylinder head including a pair of inlet fasteners passing through the insert within the regions of said inlets and an outlet fastener passing through said insert between said bridge portions of the reinforcing ribs, the lateral openings within the several fasteners connecting with the interior of the insert between the upper and lower walls thereof.

4-. The assembly as defined in claim 2 wherein each of said reinforcing rib means is of serpentine configuration, one of said rib means having a pair of arcuate limb portions closely spaced from opposed portions of said valve port walls and interconnected by a bridge portion, the other of said rib means having a pair of spaced arcuate limb portions with such limb portions diverging from the opposed wall portions of the valve port walls forming relatively unrestricted passageways therewith.

5. In an internal combustion engine, a cylinder head having upper and lower wall portions defining a water jacketing therebetween, said lower wall portion having an upwardly projecting boss provided with a cylindrical recess, an insert of generally cylindrical form received Within and substantially and completely filling said recess but having circumferential clearance therewith, said cylinder head having inlet and outlet passages therein leading to said boss, said insert having openings therethrough aligned with said inlet and outlet passages of the head, said insert including an upper wall and a lower wall spaced from the upper wall and a cylindrical side wall interconnecting the upper and lower walls peripherally thereof, said insert also having cylindrical valve port walls extending between said upper and lower walls and provid ing said openings through the insert, reinforcing ribs extending between said upper and lower walls of said insert and dividing the interior thereof into a passage system, and means projecting through said insert removably attaching the same to said head and simultaneously connecting said passage system of the insert with the coolant system of the associated engine, said means comprising at least one hollow bolt having an enlarged head recessed within said lower wall of the insert and projected through said insert into said boss of the cylinder head, said bolt having a blind bore therein, blind at its head and leading from said water jacketing to a lateral opening in the bolt connecting with the interior of said insert between the upper and lower walls thereof.

6. The assembly as defined in claim 5 wherein said means also includes an elongate bolt passing through the cylinder head from the exterior thereof through said boss and the insert having threaded engagement with the lower wall of the insert, the last mentioned bolt having a blind bore therein, blind at the threaded end thereof and provided with a lateral opening communicating between the upper and lower walls of said insert and having its upper extremity providing a nipple externally of the cylinder head for communication to the coolant system of the associated engine.

7. In an internal combustion engine, a cylinder head having upper and lower wall portions defining a water jacketing therebetween, said lower wall portion having an upwardly projecting boss provided with a cylindrical recess, an insert of generally cylindrical form receivedwithin and substantially and completely filling said recess but having circumferential clearance therewith, said cylinder head having inlet and outlet passages therein leading to said boss, said insert having openings therethrough aligned with said inlet and outlet passages of the head, said insert including an upper wall and a lower wall spaced from the upper wall and a cylindrical side wall interconnecting the upper and lower walls peripherally thereof, said insert also having cylindrical valve port walls extending between said upper and lower walls and providing said openings through the insert, reinforcing ribs extending between said upper and lower walls of said insert and dividing the interior thereof into a passage system, and means projecting through said insert removably attaching the same to said head and simultaneously connecting said passage system of the insert with the coolant system of the associated engine, said means including an elongate bolt passing through the cylinder head from the exterior thereof through said boss and the insert having threaded engagement with the lower wall of the insert, the last mentioned bolt having a blind bore therein, blind at the threaded end thereof and provided with a lateral opening communicating between the upper and lower walls of said insert and having its upper extremity providing a nipple externally of the cylinder head for communication to the coolant system of the associated engine.

8. An insert for internal combustion engines comprising a generally cylindrical member having spaced upper and lower walls interconnected by peripheral side walls, said upper and lower walls having a first pair of aligned openings therein spaced laterally from each other and on a common diameter of the insert and also having a second pair of aligned openings, a pair of cylindrical valve port walls extending between said upper and lower walls and aligned with said second openings to provide passages vertically through the insert, said valve port walls being disposed on a common diameter, each spaced laterally from the center of the insert and generally at right angles to the diameter containing said first openings through the insert, a pair of reinforcing ribs extending between the upper and lower walls of the insert, said reinforcing ribs being spaced on both sides of the center of the insert and each of said reinforcing ribs having a central portion extending between the first mentioned openings through the insert and having opposite end portions cooperating with the valve port walls to form passages substantially therearound and isolating the first mentioned openings from direct communication, said upper and lower walls having aligned openings therein between said central portions of the reinforcing ribs, said first openings and the last mentioned openings providing the opposite ends of a coolant flow path through said insert.

9. The assembly as defined in claim 8 wherein both of said reinforcing ribs are similarly formed, each having a pair of generally arcuate wing portions interconnected by an arcuate bridge portion, the bridge portions of the two reinforcing ribs being disposed in spaced relation to but adjacent to the center of the insert, one side of each wing portion being concave and substantially uniformly spaced from the opposed portions of the valve port walls, each having a further side of convex configuration substantially uniformly spaced from the inner surface of the said side wall and with the remaining sides of the wing portions of each pair being spaced from each other and diverging slightly from each bridge portion.

10. The assembly as defined in claim 8 wherein one of said reinforcing ribs includes a pair of limbs of sub stantially uniform thickness, each being arcuate and closely spaced from opposed portions of the valve port walls to define passages therewith, such limbs being interconnected by a bridge portion disposed closely adjacent to but spaced to one side of the geometric center of said 11 insert, the other reinforcing rib including a pair of generally arcuate limbs of substantially uniform thickness disposed on but to the other side of the said geometric center of the insert, the last mentioned limbs being divergent with respect to the opposed portions of the valve port walls to form therewith relatively unrestricted passages.

References Cited in the file of this patent UNITED STATES PATENTS 12 Eberle Feb. 17, 1925 Marigold Oct. 6, 1925 Regenbogen Mar. 22, 1927 Flynn Feb. 28, 1956 Ware et al Mar. 27, 1956 FOREIGN PATENTS Great Britain Dec. 22, 1921 Great Britain Jan. 18, 1923 

1. IN AN INTERNAL COMBUSTION ENGINE AND INCLUDING A CYLINDER BLOCK HAVING A COMBUSTION CHAMBER AND A CYLINDER HEAD REMOVABLY ATTACHED TO THE BLOCK AND CLOSING SAID CHAMBER, SAID HEAD BEING HOLLOW IN THE REGION ABOVE SAID CHAMBER, AN INSERT RECEIVED IN SAID CYLINDER HEAD AND FORMING AT LEAST A PORTION OF THE COMBUSTION CHAMBER THEREOF, SAID INSERT BEING HOLLOW, AND MEANS REMOVABLY ATTACHING SAID INSERT TO THE CYLINDER HEAD INCLUDING MEANS BY WHICH THE INTERIOR OF THE INSERT IS CONNECTED TO THE INTERIOR OF SAID HEAD. 